<!DOCTYPE html>
<html lang="en">

<head>
    <meta charset="UTF-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
</head>

<body>
    <script>
        let obj = {};
        obj.name = 'Jack';
        obj['age'] = 18;
        obj.sayHello = function () {
            console.log('Hello!');
        };
        obj['sing'] = function () {
            console.log('大海');
        }
        console.log(obj.name);
        console.log(obj.age);
        obj.sayHello();
        obj.sing();
    </script>
</body>

</html>